The purpose of this paper is to present and evaluate a tool designed to assess the performance of military teams participating in complex military training exercises and to investigate the effectiveness of simulator training and live training from the matching of inherent stressors. Specifically, this study evaluates a tool that has been used by Norwegian military subject matter experts (SMEs) to assess the performance of eight cadet teams at the Royal Norwegian Naval Academy (RNoNA) during two separate 4-hour simulator exercises and a 48-hour live exercise. The resulting positive Spearman rank correlation coefficients between team performance assessments in the simulator exercises and the live exercise were strongest when the simulator scenario emphasized the stressors inherent in the live exercise and weakest when the simulator scenario did not facilitate the task demands in the live exercise. The study showed that (1) team performance measured in simulator training exercises can predict performance in a subsequent live training exercise, and (2) that scenario-based simulator training can realistically and effectively represent training demands for live operations. Our findings show the RNoNA tool can be easily applied to team training exercises and provide a meaningful evaluation of a team's future performance.